A Raman spectroscopic study on the hydrogen\|bond defect of water in 2\|hydroxyethyl (meth)acrylate hydrogels crosslinked by ethylene glycol dimethacrylate (EGDMA) and polyethylene glycol dimethacrylates were undertaken.It was found that PEGDMA 16 possessed a different behavior on the hydrogen\|bond defect from EGDMA and PEGDMA 9.That is,the extents of hydrogen\|bond defect for EGDMA and PEGDMA 9 decreased with the increase of crosslinking density,whereas for PEGDMA 16,as the crosslinking density is bigger than a certain value,the hydrogenbond defect is increased with the increase of crosslinking density.This is caused by the weaker effect of —CH 2OCH 2— in the PEGDMA 16 to the hydrogen\|bond defect of water than that of —OH in HEA and HEMA.
